Structural and magnetic properties of Cr3+ doped Mg ferrites

The polycrystalline MgCrxFe2–xO4 ferrites (0.0 x 1.0) were prepared by conventional solid state ceramic sintering technique in air at 1300˚C. X-ray diffraction experiments were carried out on all the samples in order to characterize the materials at room temperature. The X-ray diffraction patterns showed sharp peaks indicating the formation of single phased cubic spinel structure. The lattice parameters of the samples were determined from the X-ray diffraction data using Nelson-Riley extrapolation method. It was found that the lattice parameter decreased with increasing Cr concen-tration obeying Vegard’s law. Magnetic properties of the samples were measured using an Impedance Analyzer. Real and imaginary parts of the complex permeability, loss factor and quality factor were measured as the function of fre-quency at three different sintering temperatures 1250˚C, 1300˚C and 1350˚C for all the samples in the frequency range 1 kHz to 13 MHz. Frequency stability of the real part of permeability () increases with increasing Cr concentration and also with sintering temperature. Imaginary part of permeability () decreases with increasing frequency and in-creased with increasing both of the Cr content and sintering temperature. Loss factor (tan) decreased with increasing frequency while the quality factor (Q) increased with increasing frequency for all the samples. The temperature de